Signaling system



June 17, 1924; 1,498,238

N. H. HOLLAND SIGNALING SYSTEM Filed July 13; 1920 2 Sheets-Sheet 1 a a 7 I ,1 A L l? L j Z r J 1] y j j I l 2; f

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N. H. HOLLAND SIGNALING SYSTEM Filed July 13 1920 2 Sheets-Sheet 2 III/IIl Il Il Patented June E7, 1924.,-

NEWMAN H. HOLLAND, OF WEST ORANGE, NEW JERSEY, ASSIG-NOR TO NEW 3' 1 1 I was PATENT COMPANY, OF WEST ORANGE, NEW JERSEY, A CORPORATION OF NEW JERSEY.

SIGNALING SYSTEM.

Application filed July 13, 1920. Serial No. 395,897.

To all whom it may concern:

Be it known that I, NEWMAN H. HoL- LAND, a subject of the King of Great Britain, and a resident of West Orange, Essex 5 County, New Jersey, have invented certain new and useful Improvements in Signaling Systems, of which the following is a description.

My invention relates to signaling systems and more particularly to automatic railway block signaling systems wherein track circuits containing or associated with relays or the like are employed to control the signal circuits or signal-control circuits; the present invention in some aspects being an improvement on the invention disclosed in a copending application V Isaac P. Rodman, Serial No. 391,102, fi ed June 23, 1920, and entitled Signaling sy ent No. 1,405,005 was granted on January 31, 1922.

In practically all signaling systems of this character now in use, the track circuits are supplied either with direct current from primary or storage batteries, or'withalternating current of given frequencies fed thereto from high voltage transmission lines by transformers. \Vhere direct-current track circuits are used, there is more or less danger of failure of operation of the signal for agiven block or track section, by reason of the entrance of stray currents into the corresponding track circuit from outside sources, such, for example, as an adjacent track circuit. \Vhere alternating-current track circuits are employed, the same are. of course, immune to stray direct currents, but are apt to be seriously affected by stray alternating currents coming from sources wholly outside the signaling system. This is due to the fact that the great majority of alternating-current circuits now used are supplied with commercial alternating currents at certain frequencies and alternating currents of the same frequencies are often used in alternating-current signaling systems. Moreover, the present-day types of alternating-current signaling systems are of high initial cost and comparams, on which Pat-- tively complex due to the necessity of usin large central power houses usually provided with alternating-current generating apparatus in duplicate, substantially constructed high power transmission lines, transformers, impedance bonds, polarized circuits, linecontrol circuits, etc.

One of the principal objects of my invention is to provide an improved, and an extremely simple and efiicient signaling system which has all the advantages of present-day alternating current railway signaling systems as regards interference by stray or foreign direct currents, which will be unaffected by stray currents from alternating-current circuits supplied with com mercial alternating currents, and wherein it is unnecessary to employ polarized circuits, or line-control circuits, or a transmission line for supplying current to the different track circuits.

Another and also one of the principal objects of my invention is to provide a signaling system of this character wherein current variations such as direct-current pulsations or alternating currents are produced in the track circuits or the circuits containing or associated with the relays for controlling the signal circuits or signal-control circuits by 'means comprising a novel type of pulsating-current generator and suitable sources of direct current such as primary or storage batteries. 1 v

A further object of my invention resides in a novel form of relay especially adapted for use in my improved signaling system.

In my copending application, Serial No. 712,180, filed May 10, 1924, and entitled Signaling systems or the like, which is a division of the present application, I have described and claimed the novel forms of pu l-,

' ElSSUEtl mary or storage batteries, current variations such as direct-current pulsations or alternating current, of a given frequency and difi'erent from the frequency of the current variations produced in any adjacent track circuit, and associating with each track circuit a relay or the equivalent for controlling the-corresponding signal circuit and tuned to the frequency of the current variations produced in such track circuit. I preferably employ as the means for producing current variations in each track circuit, a direct-current circuit supplied with current from aprimar battery or other suitable source and containing a resistance means such as a microphone, the resistance of which is variable by vibration, and a vibratory reed such as a tuning fork positioned so as to affect such resistance means by its vibration whereby direct-current pulsations of a definite period or frequency corresponding to the natural period of vibration of said reed will be roduced in such direct-current circuit. T e relay or equivalent device for controlling the corresponding signal circuit is tuned either mechanically or electrically or both mechanically and electrically, preferably the latter,

to the frequency of the current variations thus produced in the track circuit, and the arrangement is such that the frequency of the direct-current pulsations or the alternating current thus supplied to each track circuit is different from that supplied to any adjacent track circuit and also different.

from the frequencies of any stray currents such as -the commercial alternating currents usually employed for the propulsion of trains on railroads or other purposes.

Other features and objects of my invention will be hereinafter more fully described and claimed. g

In order that my'invention may be more clearly understood, attention is directed to the drawings accompanying and forming a art of this specification, and in which:

igure 1 is a diagrammaticview illustrating a portion of one form of an automatic railway block signaling system in accordance with my invention, in which the relays for controllingthe signal cir cults are respectively mechanically and electrically tuned to the frequency of the current variations produced in the track circuits;

Fig. 2 is a diagrammatic view illustrating a modification of the system shown in Fig. 1, in which the relays controlling the signal circuits are mechanically tuned to the current variations produced in the corresponding track sections;

Fig. 3 is a view similar to Fig. 1, showing another form of signaling system in accordance with my invention, in which the relays controlling the signal circuits are electrically tuned to the current variations produced in the corresponding track circuits; and

Fig. 4 is a View illustrating a sh ht modification of the system shown in Pig. 3.

Referring to the drawing and especially to Fig. 1, reference characters A, B and U represent three track sections or blocks of a signalingsystem in accordance with my invention, and S the signal associated with and disposed at the entrance of the section or block B for governing the same; it being understood that similar signals are disposed at the entrance of all other blocks of the system. Reference character M represents a primary battery one side of which is connected to one rail 1 of the) section B at the exit end thereof by means of conductor 2, and the other side of which is connected to the rail 3 of section B at the exit end thereof through conductor 4:, con ductor 5, microphone 6 and conductor 7. The microphone 6 is mounted on a suitable support E, on which is also mounted a vibratory reed such as a tuning fork? 8. An electro-magnet 9 is disposed adjacent one leg of the tuning fork 8, and one end of. the 'coil of this electro-magnet is connected to one side of the battery M through conductors 10 and 2, while the other end of said coil is connected to the other side of the battery M through conductor 11, microphone 12 and conductors 13 and 4. The microphone 12 is also mounted on the support E and it will accordingly be apparent that both of the microphones 6 and 12 will be affected by vibrations of the tuning fork. At the entrance end of the section or block B, the rails 1 and 3 are respectively connected by means of conductors 14 and 15 to the primary 16 of a transformer, the secondary 17 of the transformer being connected in circuit with the electromagnet 18 .of-a relay. The armature of the relay consistsof a vibratory reed, preferably a tuning fork 19, mounted in a suitable support F and having the same natural period of vibration as the tuning fork 8. This tuning fork 19 controls a switch located in the signal or signal-control circuit for signal S and comprising two spring contacts 20 and 21 which are fixed at one end. The spring contact 20 comprises two arms 22 and 23, and normally assumes a position with its arm 22 engaging one leg of the tuning fork 19 and with its arm 23 in opposed spaced relation at its upper end to the upper end of the springcontact 21. Suitable means is provided for effecting a relative adjustment of the contacts 20 and 21, this means as shown consisting of a screw 24 threaded through a suitable support and coacting with the contact 21 to effect adjustment of the upper end of the latter towards and away from the upper end of the arm 23 of the contact 20. Reference character N represents a suitable source of current such as a primary or storage battery for supplying current to the signal or signal-control circuit, one side of the battery being connected to the motor, (not shown) disposed in the casing G, for actuating the signal S, by means of conductor 25, and the other side thereof being connected to contact 20 of switch K by conductor 26. The signal actuating motor in casing G is also connected to switch, contact 21 by means of conductor 27. When the signal or signal-control circuit is opened, the signal actuating motor in casing G will, of course, cease to operate and the signal S will thereupon under the action of gravity drop to danger position as shown; but when this circuit is closed, the motor will move the signal S to and hold the same in clear position as indicated in dotted lines.

The operation of that forin of my invention shown in Fig. 1 is as follows: Direct current is continuously supplied to the track circuit section B over the following path: from battery M through conductor 2, rail 1, and conductor 14 to the primary 16 of the transformer, then through conductor 15, rail3, conductor 7, microphone 6, conductor 5 and conductor 4 back to the battery. Direct current will also be continuously supplied to a second circuit over the following path: from the battery M through conductor 2, conductor 10, the coil of electro-magnet 9, conductor 11, microphone 12. conductor 13 and conductor 4 back to the battery. This second circuit together with the tuning fork 8 disposed in operative relation to the electro-magnet9 comprise a pulsating current generator, for when this circuit is made, the electro-magnet 9 attracts the tuning fork 8 and starts the same Vibrating in its natural period, the tuning fork 8 in vibrating, vibrates the support E and microphone 12, thereby producing changes or variationsin the resistance of the microphone 12 corresponding in frequency to the vibrations of the tuning fork which in turn effects current variations or pulsations in the circuit including the coil of electromagnet 9. It is therefore apparent thatthe tuning fork will be continuously vibrated in its natural period as long as said circuit is closed and supplied with current. The vibrations of the tuning fork 8 also effect variations of the same frequency in the resistance of the microphone 6, and accordingly direct-current pulsations of a frcquency corresponding to the frequency of the natural period of vibration of the tuning fork 8 are produced in the track circuit including the primary 16 of the transformer. Of course, it is not necessary to connect the electroanagnet 9 and microphone 12 in shunt with the track circuit as shown, for the same results may be obtained byusing a single microphone and connecting the same and the electro-magnet in series with the track circuit. Obviously alternating current of a frequency corresponding to the frequency ofthe direct-current pulsations in the track circuit, will be produced in the circuit of the secondary 17 of the transformer and the electro-Inagnet 18 of the relay controlling the signal or signal-control circuit. The re-. lay is suitably electrically tuned to the frequency of the alternating current thus produced in the circuit of the secondary 17 of the transformer and the electro-magnet 18, and, therefore, to the frequency of the direct-current pulsations in the track circuit and to the natural period of vibration of tuning fork 8, as by means of an adjustable condenser D in the circuit of the secondary 17. The tuning fork 19 comprising the armature of the relay, being of the same natural period of vibration as the tuning fork 8, the relay is also mechanically tuned to the frequenc of the alternating current in the circuit of the electro-magnet 18 and secondary 17 of the transformer and, therefore, to the frequency of the direct-current pulsations produced in the track circuit by the pulsating-current generator. The tuning fork 19 will, therefore, assuming the section or block B to be unoccupied, be vibrated in its natural period and, by reason of the engagement of one leg thereof with the arm 22 of the spring contact 20, will normally maintain the latter in circuit closing position with the arm 23 thereof in engagement with the spring contact 21. In this connection it is to be noted that the spring contact 20 should have a natural period of vibration different from and preferably much less than the natural period of vibration of the tuningfork 19. Switch K thus being maintained closed, current will be supplied to the signal actuating motor and the signal S will be normally held'in clear position as explained above. When a. train T moves into the section or block B, as shown, the primary 16 of the transformer will be short-. circuited and accordingly the e-lectro-magnet 18 of the relay will be de-energized. The tuning fork 19 will thereupon cease to vibrate, the spring contact 20 of switch K will move to and remain in open position, the motor in casing G will cease to operate and the signal S will, under the action of gravity, drop to danger position, as shown. hen the train T moves out of the section or block B, the relay controlling the signal or signal-control circuit will again be operated as above described, said circuit will be closed and the signal returned to clear position.

primary. 29 of a transformer.

trol circuit for signal S is only mechanically tuned to the direct-current pulsations produced in the track circuit instead of being both mechanically and electrically tuned thereto. In the system as shown in this figure, the railsl and3of section or block B, are directly connected at the entrance end of the section by means of conductors 14 and 15', respectively corresponding to the conductors 14 and 15 shown in Fig. l, to the coil of the electro-magnet 18 of the relay for controlling the signal or signal-control circuit instead of to the primary of a transformer. Accordingly, direct-current pulsations of a frequency corresponding to the frequency of the tuning fork of the pulsating-current generator are produced in the circuit of the coil of the electro-n'lagnet 18. Therefore in this form of my invention, the relay of which the electro-magnet 18 is a part, is tuned to the direct-current pulsations produced by the pulsating-current generator only by reason of the fact that the tuning fork 19 comprising the armature of the relay has the same naturaul period of vibration as the tuning fork of such generator. It will be apparent that when the section B is unoccupied, the electro-magnet 18' will be supplied with directcurrent pulsations and effect the vibration of the tuning fork 19 in its natural period. Except as just described, the construction, arrangement and operation of this form of my invention and that shown in Fig. 1 are the same.

In the modification shown in Fig. 3 the relay for controlling the signal or signalcontrol circuit for signal S is only electrically tuned to the direct-current pulsations produced by the pulsating-current generator, instead ofbeing mechanically and electrically tuned thereto. In this form of my invention, the conductors 2' and 7, respectivaly corresponding to the conductors 2 an of being respectively connected to the rails 1 and 3 of section B, are connected to the The secondmy of this transformer is connected by conductors 31 and 32 across the rails 1 and 3 of the section B at the exit end thereof, and said rails are respectively connected at the entrance end of the section B by means of conductors 14 and 15 to the terminals of the coil of the electro-magnet 18 comprising a part of the relay for controlling the signal or signal-control circuit for si al S. The armature of the relay consists o a pivoted arm 33 constituting a part of a switch K in the signal, or signal-control circuit. In this form of my invention the track circuit is as follows: from one terminal of the secondary 30 through conductor 31, rail 1, conductor 14 the coil of electro-magnet 18 conductor 15 rail 3 and conductor 32, to the other terminal of the secondary 30. It

of'the system shown in Fig. 1, instead.

'will be apparent that direct-current pulsacuit being as follows: from the battery M through conductor 2', primary 29, conductor 7, microphone 6, conductor 5 and conductor 4 back to the battery. Alternating current of a frequency corresponding to the frequency of the direct-current pulsations in the circuit of the primary 29 will therefore be produced in the track circuit including the secondary 30 of the transformer, and when the section or block B is unoccupied, the electro-inagnet 18 will be energized, for the latter is: suitably electrically tuned, as by means of the adjustable condenser D, to alternating current of such frequency. The armature 33 will thereupon be moved to a position closinggthe signal or signal-control circuit for signal S and the latter will accordingly be moved to clear position. When a train T is present in the section or block B, the electro-magne't 18 will be shortcircuited, whereupon the armature 33 will automatically move to a position opening the signal-control circuit, and the signal will move to danger position, as shown.

Fig. 4 illustrates a slight modification of the system shown in Fig. 3, in which the conductors 14 and 15 respectively corre sponding to the conductors 14 and 15 of Fig. 3, instead of being directly connected to the coil of the electro-magnet 18 of the relay controlling the signal or signal-control circuit, are connected to the primary 34 of a transformer. The secondary 35 of this transformer is connected by conductors 36 and 37 to the terminals of the coil of the electro-magnet 18 of the relay. Suitable means such as an adjustable condenser D is connected in circuit with said coil for the purpose of electrically tuning the relay to the frequency of the alternating currents produced in the circuit of said coil, and the track circuit, and therefore to the frequency of the direct-current pulsations produced in the circuit of the primary 29 as well as to the frequency of the vibrations of the tun-. ing fork 8 of the pulsating-current generator. The purpose of the transformer comprising the primary 34 and secondary 35 is described the circuit connection for only in a similar manner, are provided for all other sections or blocks. The arrangement is such, however, that the pulsating-current generator associated with any section produces current pulsations of a frequency different from that of the current pulsations produced by-the pulsating-current generator associated with any adjacent block, whereby there will be no danger of the relay for any section being afl'ected by stray currents from the circuit connections of any adjacent section.

While I have shown several embodiments of my invention, it is to be understood that these are for the purposes of illustration only and that such embodiments are subject to numerous changes and modifications without departure from the spirit of the invention and the scope of the appended claims.

Having now described my invention, what I claim as new and desire to protect by Letters Patent of the United States, is as follows closed circuit, means comprising a vibratory.

reed for producing current pulsations of a given frequency in such circuit, a signal circuit, and means for controlling said signal- I circuit comprising a device normally in op erative relation to said direct-current cir cuit and tuned to the frequency of the current pulsations in the latter, the presence of a train in a block with whichsaid signal circuit is associated, placing said device in inoperative relation to said direct-current circuit, substantially as described.

2. In an automatic railway block signaling system, a signal circuit, and means for controlling said signal circuit, comprising a direct-current constantly" closed circuit, means comprising a vibratory reed for producing current pulsations of a given frequency in said direct-current circuit, and a relay normally in operative relation to said I direct-current circuit and tuned to the frequency of the current pulsations in the latter for controlling the signal circuit, the presence of a train in a block with which the signal circuit is associated, placing said relay in inoperative relation to said direct-current circuit, substantially as described.

3. In an automatic railway block signal ing system, a signal circuit, a direct-current constantly closed circuit, means comprising a vibratory reed for producing current pulsations of a given frequency in said directcurrent circuit, the track section of the block with which said signal circuit is associated being electrically associated with said directcurrent circuit whereby current variations of a frequency corresponding to the frequency of the pulsations in the direct-current circuit are produced in said track section, and a relay tuned to the frequency of the current-variations produced in the track section for controlling the signal circuit, said relay being electrically associated with said track section so as to be normally responsive to the current variations produced in the latter, the presence of a train in said track section rendering said relay unre-' sponsive to the said current variations, substantially as described.

4. In an automatic railway block signaling system, a signal circuit for each of a plurality of blocks, and means for controlling each signal circuit comprising a directcurrent constantlyplosed circuit, means comprising a vibratory reed for producing current pulsations of a given frequency in said direct-current circuit, and a relay normally in operative relation to said direct-- current circuit and tuned to the frequency of the current pulsations in the latter, the presence of a train in a corresponding block placing said relay in inoperative relation to said direct-current circuit, the frequency of the current pulsations produced in the said direct-current circuit for any given block being different from that of the current pulsations produced in the direct-current circuit for any adjacent block, substantially as de scribed. L

5. In an automatic railway block signaling system, a direct-current I constantly closed circuit, means for producing current pulsations of agiven frequency in such circuit, a signal circuit, and means for con-, trolling said signal circuit comprising a device normally in operative relation to said direct-current circuit and mechanically tuned to the frequency of the current pulsations in the latter, the presence-of a train in a block with which said signal. circuit is associated, placing said device in inoperative relation to said direct-"current circuit, substantially as described.

6. In an automatic railway block signaling system, a direct-current constantly closed circuit, means for producing current pulsations of a given frequency in such circuit, a signal circuit, andmeans for controlling said signal circuit comprising a device normally in operative relation to said direct-current circuit and mechanically and electrically tuned to the frequency of the current pulsations in the latter, the presence of a train in a block with which said signal circuit is associated, placing said device ininoperative relation to said direct-current circuit, substantially as described.

7. Inan automatic block signaling system, a signal circuit for each of a .plurality of blocks, and means for controllingeach signal circuit comprising a direct-current constantly closed circuit, means comprising a vibratory reed for producing current pulsations of a given frequency in said direct-current circuit, and a relay which is normally in operative relation to said direct current circuit and which comprisesa reed tuned to the frequency of said current pulsations, the presence of a train in the corresponding block placing said relay in inoperative relation to said direct-current circuit, substantially as described. I

8. In an automatic railway block signaling system, a direct-current constantly closed circuit, means comprising a vibratory reed for producing current pulsations of a given frequency in such circuit, a signal circuit, and means normally in operative relation to said direct current circuit for controlling said signal circuit and comprising a reed tuned to the frequency of said current pulsations, the presence of a train in a block with which said signal circuit is associated, placing said controlling means in inoperative relation to said direct-current circuit, substantially as described.

9. In an automatic railwayblock signaling system, a direct-current constantly closed circuit including the primary of a transformer, a circuit including the secondary of the transformer, the rails of a block or track section being included in one of said circuits, means for producing direct current pulsations of a given frequency in the said primary included in the directcurrent circuit whereby an alternating current of the same frequency is produced in the other of said circuits, a signal circuit, and a relay for controlling said signal circuit associated with the circuit in which the alternating current is produced, said relay being tuned to the frequency of said alternating current, substantially as described.

10. In an automatic railway block signaling system, a direct-current constantly closed circuit including the primary of a transformer, a circuit including the secondary of the transformer, the rails of a block or track section being included in one of said circuits, means for producing current pulsations of a given frequency in the direct-current circuit whereby an alternating current of the same frequency is produced in the other of said circuits, a signal circuit, and a relay for controlling said signal circuit associated with the circuit in which the alternating current is produced and mechanically tuned to the frequency of said alternating current, substantially as described.

11. In an automatic railway block signaling system, a direct-current constantly closed circuit including the primary of a transformer, a circuit including the secondary of the transformer, the rails of a block or track section being included in one of said circuits, means for producing current pulsations of a given frequency in the direct-current circuit whereby an alternating current of the same frequency is produced in the other of said circuits, a signal circuit, and a relay for controlling said signal circuit associated with the circuit in which the alternating current is produced and mechanically and electrically tuned to the frequency of said alternating current, substantially as described.

12. In an automatic railway block signaling system, a direct-current constantly closed circuit. including the primary of a transformer, a circuit including the secondary of the transformer, the rails of a block or track section being included in one of said circuits, means for producing current pulsations of a given frequency in the directcurrent circuit whereby an alternating current of the same frequency is produced in the other of said circuits, a signal circuit, and a relay for controlling said signal circuit associated with the circuit in which the alternating current is produced and having an armature consisting of a vibratory reed the natural period of vibration of which corresponds to the frequency of said alternating current, substantially as described.

13. In an automatic railway block signaling system, a direct-current constantly closed circuit including the primary of a transformer, a circuit including the secondary of the transformer, the rails of a block or track section being included in one of said circuits, means comprising a vibratory reed vi brated at its natural period for producing current pulsations of a given frequency in the direct-current circuit whereby an alternating current of the same frequency is produced in the other of said circuits, a signal circuit, and a relay for controlling said signal circuit associated with the circuit in which the alternating current is produced and tuned to the frequency of said alternating current, substantially as described.

14. In an automatic railway block signaling system, a direct-currentcircuit including the 'rimary of a transformer, anda circuit inc uding the secondary of the transformer, the rails of a block or track section being included in one of said circuits, means comprising a vibratory reed vibrated at its natural period and a microphone in said direct-current circuit positioned so as to be affected by the vibrations of said reed, for producing current pulsations of a given frequency in the direct-current circuit whereby an alternating current of the same frequency is. roduced in the other of said circuits, :1 signa circuit, and a relay for controlling said signal circuit associated withthe cir- 125 cuit in which the alternating current is produced and tuned to the, frequency of said alternating current, substantially as described.

15. In an automatic railway block signaling system, a direct-current constantly closed circuit, resistance means included in said circuit, the resistance of which is affected by vibration thereof, means for vibrating said resistance means to thereby produce current pulsations of a given frequency in said direct-current circuit, a signal circuit, and means for controlling said signal circuit comprising a device normally in operative relation to said direct-current circuit and tuned to the frequency of the current pul- 10 sations in the latter, substantially as described.

This specification signed this 6th day of July, 1920.

NEWMAN HOLLAND. 

